The paper is organized as follows. Section  describes the formulation of characteristic modes using the scattering dyadic along with high-level connections to formulations involving the transition matrix [1]} and system (impedance) matrices [2]}. In Section , practical aspects of collecting necessary scattering dyadic data using MoM, FEM, and FDTD are discussed. In Section , example calculations involving PEC structures as well as those involving dielectric and magnetic materials are used to demonstrate the method's efficacy and to draw general conclusions about the application of different solvers in calculating characteristic modes. Important aspects of the method are discussed in Section . Section  concludes the paper with discussion points and open problems. The paper is accompanied by supplementary material containing wrappers for several contemporary EM simulation packages (CST Studio Suite [3]}, Altair FEKO [4]}, Ansys HFSS [5]}, COMSOL Multiphysics [6]}).
